The invention relates to a belt system for restraining a vehicle occupant.
Belt systems have been proposed, in which the safety belt is constructed as a tube which is inflated in the case of restraint. Through this tube, a certain tensioning effect is achieved and also a type of damping is made possible on restraining, so that as a whole the risk of injury is reduced. Hitherto, the provision of such inflatable tubes was always directed to replace belt retractors.
The invention provides a belt system which makes possible an even better restraining of the occupant in the case of a crash. This is achieved in a belt system which comprises a safety belt, a belt buckle, two end fittings, at least one belt retractor, at least one inflatable belt gas bag and at least two belt tensioners. At least one of the belt tensioners is an end fitting tensioner. The invention provides, in combination with a belt gas bag, not only one but two tensioners, whereby the tensioning path can be relatively large. In belt gas bags, in fact, the danger would exist that the safety belt and hence the gas bag are displaced too much if only one tensioner with a very long tensioning path were used, which can result in problems with regard to the flow of gas with a simultaneous inflation of the belt gas bag. In addition, for example a retraction tensioner can only have a very small tensioning path when it has to wind up an inflated tube. By providing two tensioners, the position of the gas bag can remain relatively unchanged in the region of the body. The provision of an end fitting tensioner is very crucial here, because an end fitting tensioner, which also includes a retraction tensioner, but not a buckle tensioner, provides for a relatively stable position of the occupant, as has been proved in tests.
Preferably, the end fitting tensioner is a retraction tensioner. Furthermore, two belt retractors can also be provided, which if necessary are both even constructed as retraction tensioners. Thereby, it is possible to completely wind up the safety belt, which has a relatively large volume, when it is constructed as an inflatable tube.
In addition, it is conceivable to combine and end fitting tensioner with a buckle tensioner.
The safety belt can be constructed as an inflatable tube or as an inflatable hollow body fastened to the safety belt.
To inflate the belt gas bag, at least one gas generator is provided, which is arranged fixed to the vehicle. Fixed to the vehicle means that it is fixed to the frame of the vehicle and is not, for instance, arranged on a movable part.
In addition, it is also intended that a gas generator can inflate a plurality of units, namely for example a belt gas bag and at least one tensioner.